A Parathyroid scan is used to identify and localize patients with hyperparathyroidism or overactive parathyroid glands looking for a parathyroid adenoma. There are no special preparation instructions for this scan. When you arrive, the technologist will explain the exam and will inject a tiny radioactive substance in your vein that is taken up by parathyroid adenomas. You will not feel anything from the radioactive substance and will be scanned twice. Feel free to call us if you have any questions regarding this exam.